Warming enhances the negative impact of shrubs on community stability via reducing species asynchrony

Numerous studies have demonstrated that climate warming and the presence
of shrubs affect herbaceous plant community composition and function.
However, how the temporal stability of herbaceous plant community biomass
responds to combinations of warming and the presence of shrubs remains
largely unexplored. The effects and mechanisms of simulated warming and
shrubs on the community stability were investigated in a 5-year field
experiment in alpine grasslands. Our results showed that warming alone or
shrubs alone reduced community stability by decreasing species richness
and temporal asynchrony. Additionally, warming alone or shrubs alone
reduced community stability by decreasing community-weighted means of leaf
dry matter content of species. We also found that the interaction of
warming and shrubs had a cumulative negative effect on plant community
stability by increasing species synchrony. Synthesis: Our study suggests
that continued global warming and shrub expansion may negatively affect
the stability of natural grassland functions and services, and highlights
the importance of temporal asynchrony and traits among species in
moderating the effects of global change on ecosystem stability.